The myth of primitive societies.
Humans who live in technologically primitive societies aren’t as intelligent as those who live in advanced societies…or so some of histories most influential personalities thought. The reasoning behind their thinking, when it was used as an honest theory and not a egocentric attack on another culture to legitimize their enslavement or destruction, is that primitive societies just harvest what is naturally provided, so while they have to physically work for their resources, there isn’t much innovation in the techniques used to collect and store it, and because there is no innovation the brain doesn’t develop all the skills that it would have if the person was forced to innovate–in short making the person less intelligent.